1. Field of the Invention
The present invention relates to a motor fan for a cleaning apparatus, and more particularly to the motor fan whose deformation can be prevented, thereby providing the improved reliability and suction efficiency of the fan, and further, the motor efficiency being guaranteed even if any gap between fins on the fan and a motor housing is not adjusted.
2. Description of the Prior Art
Generally, there are now provided various types of a cleaning apparatus adopted to clean a room by sucking the dirt and dust through the suction created by a driving motor mounted in a main body of the cleaning apparatus.
As shown in FIGS. 1 and 2, the cleaning apparatus includes a main body 1, a dust collection compartment 5, a driving compartment 7, and a suction hose 4. The main body 1 forming a general exterior appearance of the cleaning apparatus further includes a connecting portion 2 and an exhaust outlet 3. The dust collection compartment 5 has a dust collection bag 6 used for collecting dust and foreign materials sucked into the body 1. The driving compartment 7 includes sucking means 10 mounted therein through supporting member 8, for creating the suction. Finally, the suction hose 4 coupled to the body through the connecting portion 2 serves to guide the air flow containing the dirt and dust into the dust collection bag 6 during the operation of the cleaning apparatus.
Further, the sucking means 10 has lower and upper housings 11 and 17, both of which form a general appearance thereof. The lower housing 11 is provided with a rotor 12 therein, which is for creating the rotational force during an application of electric power thereto. The upper housing 17 coupled to the lower housing 11 is provided with a fan or impeller therein that creates the actual suction in the cleaning apparatus by the activated rotor 12. The upper housing 17 also has a suction inlet 18 generally positioned around a hub thereof and a plurality of air outlets 19 formed in an outer surface thereof.
Also, the rotational force from the rotor 12 is transmitted through a shaft 13 coupled thereto to the fan 100, in which the shaft 13 has one end portion to which a male screw 15 is integrally attached, together with a stepped portion 14 on said end portion.
Referring to FIGS. 3 and 4, one side of the fan 100 is provided with many curved fins 110 as integral parts of the fan 100, which cause the air in the dust collection compartment 5 to pass through the suction inlet 18 by the suction when the fan coupled to the rotor is rotated, and to discharge the sucked air outside the body 1 through the outlets 3 and exhaust outlet 19.
The fan 100 includes at central portion or hub thereof a groove 120 to be fitted into the stepped portion 14 and a through hole 130 contiguous to the groove 120, and for inserting the male screw 15.
The groove 120 and stepped portion 14 support a lower part of the fan 100, while an upper part of the fan 100 is assembled by using the screw. Then, nut 16 is used to tighten the screw 15.
However, such a configured fan has several problems. The fan 100 coupled to the shaft 13 only by nut 16 without a separate supporting means suffers from downward load applied thereto. With torque beyond a predetermined pressure being loaded to nut 16 for fastening, heat is generated during rotation of the fan 100 and a supporting intensity is lowered accordingly. This causes deformation being bent toward the curved fins, which damages the fan 100 and reduces a suction efficiency and reliability.
Further, it is generally designed such that the curved fins 100 are spaced a constant interval from a motor cover 24 assembled with the upper housing 17. However, a satisfactory adjustment of the required interval is substantially difficult, thereby causing the drawback that suction efficiency of t he motor is lowered.